Remote control



NOV. 21, 1944. E, BARTHQLY 2,363,285

REMOTE CONTROL Filed Oct. 16, 1940 WITNESSES: INVENTOR FrederzckEBarzhoQ W BY ATTORNEY Patented Nov. 21, 1944 REMOTE CONTROL Frederick E. Bartholy, Wilkinsburg, Pa., asslgnor to Westinghouse Electric & Company, East Pi of Pennsylvania Application October 16, 1940, Serial No. 361,442

(Cl. l72239) 9 Claims.

Thi invention relates to control systems, and more particularly, to electrical systems in which the direction and the extent of the movement of the apparatus to be controlled may be automatically obtained in accordance with the direction and the extent of movement of a control instrument located nearby the controlled apparatus.

Systems of this tlon for various purposes, such as the control of location The invention is particular the simultaneous indication ---oi' an instrument at a distance point ly adaptable to the remote tuning of radio receivers in that it provides continuous progressive tuning dial by the simple ma a similar dial at a remote tion of the invention was cho movement of the nual adjustment of point. This applicasen for the purpose of illustration in order to simplify the understanding thereof, although no limitation is intended thereby for it will be readily seen that the nature of may be anything from indicating instrument.

Th principle of operation based or thermionic cathodes. discharge device known as the controlled apparatus has no bearing on the invention herein described and a large elevator to a small These devices may have cold As an example, the the grid-glow tube" and described in United States Patent No. 2,062,-

268 is particularly suitable in the present invention. A cold the above tube is shown in connection with the the invention herein described and a device or the above described general type stood by the terms tube" or wherever it is applied. The

tube to small variations talning the tube nonconductive ance exists between the two paths. The function of the is to be underdischarge tube great sensitivity of ttsbnrgh, Pa,

Manufacturing a corporation be further explained in connection with the description of the operation of the control system.

A particular feature of this invention is that when the control system is applied to remote tuning of any apparatus, for instance, a radio receiver, the tuning operation at the remote point involves merely the turning of a dial which may be graduated in kilocycles or meters in the same manner as the original tuning dial of the receiver, and that the setting thereof in any direction and to will effect the energization of the conventional tuning motorto drive the receiver tuning con denser in the same direction and to the same or any desired increment of the dial scale.

Another feature of the invention is that the control system when in standby condition, consumes no power from the supply and that the control circuit associated therewith operates merely upon capacitive change and potential charges; hence, carries no current.

An advantage of the control system in accordance with this invention resides in that only two conductors are necessary between the remotely located tunin element and the radio receiver to be controlled,

Other features and advantages will be apparent from the following description of the invention, pointed out in particularity by the appended claims, and taken in connection with the accompanying drawing, in which the single figure illustrates a schematic arrangement of the remote actuation of a tuning condenser assembly.

Referring to the figure, the apparatus to be controlled is shown here in perspective as a gang condenser l, the shaft 2 of which carries a dial 3 at one end and at the other end is connected through suitable reduction gearing to the shaft 4 of an electric motor 5. The gang condenser I is intended to represent symbolically the tuning element any small increment of the scale The motor 5 herein shown is of the dual-field type having a field winding 8 and 9, each being adapted to be energized from a source shown here by the battery H1. The field 8 is connected in series with the armature to the battery l through conductor switch contacts I2 and I2 and conductors l3 and I4, whereas the field 9 is connected to the battery H1 in series with the armature 1 through conductor ll, switch contacts l5 and I5 and conductors l3 and M. In this manner, when the switch contacts l2 and I2 are bridged, the motor is energized to rotate in one direction and when the switch contacts l5 and I5 are bridged, in the opposite direction. The bridging of the contacts I2 and I2 is effected by the relay I8 and thebridging of the contacts I5 and I5 by the relay l9. 1

The source of energization for the winding 26 of the relay I8 is the secondary winding 2| of a transformer 22. The winding 2| is connected to one terminal of the winding 26 through a resistance 24. The other terminal of the winding 2| connects to the cathode 25 of the grid-glow tube 26. The anode 21 thereof connects through conductor 28 to the other terminal of the winding 26. The latter is suitably bypassed by a condenser 29. The energizing circuit of the relay |8 between the winding 2|] and the energizing source comprising the secondary winding 2| includes in series, the resistance 24 and the cathode-anode path of the grid-glow tube 26.

The relay I9 is similarly connected in that one terminal of its winding 30 connects to one terminal of another secondary winding 3| of the transformer 22 in series with resistance 34, and the other terminal through conductor 35 to the anode 36 of a second grid-glow tube 31. The cathode 38 thereof connects through conductor 39 to the other terminal of the winding 3|. Condenser 46 is connected directly across the terminals of the winding 30.

From the above description, it is seen that the two tubes 26 and 31, respectively, are interconnected with respect to their electrodes in such manner that the control electrodes 46 and 49 are directly connected with each other, whereas the anode of one tube connects to the cathode of the other and vice versa. Such connection of tubes is generally referred to as back-to-back connection. The conductive energization of the tube 26 will permit current to flow from the winding 2| to the relay winding and, similarly, conductive energization of the tube 31 will permit current flow from the winding 3| to the relay winding 36. The circuit for energizing the gridglow tubes is shown to be alternating current obtained directly from a suitable power supply line to which the primary winding 23 of the transformer 22 may be connected. The current through the windings 26 and 30 will be pulsating direct current by virtue of the rectifying action of each glow tube. The condensers 29 and 46, in connection with their respective windings to which they are connected, act as filters or energy storing means to maintain operation of the relays l8 and I9, respectively, during the non-conducting half-cycles.

In order to control the energization of the tubes and thereby the operation of the relays I8 and IS, a capacitive control circuit is provided between electrodes of the respective tubes in that a condenser 42 is connected through conductors 43, 44 and 45, between grid 46, and anode 21 of tube 26, and another condenser 41 through conductors 44, 45 and 48, between anode 36 and grid 49 of the tube 31. The condenser 41 is mechanically interlinked with the tuning condenser and rotates simultaneously therewith. The cathode of tube 26 is interconnected through conductor 50 with the anode 36 of tube 31 and correspondingly the anode 21 of tube 26 through conductor 5| with the cathode 38 of tube 31. Through this interconnection, the condenser 42 while connected between anode 21 and grid 46 of tube 26, is also effectively connected between grid 49 and cathode 38 of tube 31. Similarly, the condenser 41 while connected to the anode 36 and grid 49 of tube 31, is also effectively connected to the cathode 25 and grid 46 of tube 26. In par- P allel with each condenser 42 and 41 are condensers 52 and 51, respectively.

Before describing the operation of the system, let it be mentioned again that the action of the grid-glow tube as to initiation of space current conductivity depends upon the leakage between its grid-anode and grid-cathode path. A lower resistance path between grid and anode as, for example, an increase of capacity, will cause a state of conductivity whereas a similar path between its grid and cathode, will nullify the above effect. Moreover, an increase of the leakage between grid and cathode will bias the tube in lowering its sensitivity to conduction until this path is counter-balanced or offset by an increase in the leakage between grid and anode of the tube. A leakage path may be provided eitherby an ohmic resistance or by an impedance such as an inductance or a capacity. The latter was chosen here in illustrating a preferred embodiment of the invention because capacitive leakage elements have certain practical advantages. To mention a few, variable condensers of the type generally used in circuits may be employed and thereby the calibration of the remote dial made uniform with that of the tuning dial of the receiver. The use of variable resistances or inductances introduces certain mechanical diificulties particularly in obtaining a certain uniform rate of change in the resistance or impedance value between two components. However, no limitation is intended in showing variable condensers as the leakage elements.

Following the circuit herein shown, it is seen that the condenser 42 provides a certain leakage path between grid and anode of the tube 26 depending upon its particular capacitive adjustment, and that this path may be counterbalanced by the condenser 41 which provides a leakage path between grid 46 and cathode 25 of the same tube. At a particular setting, the two condensers provide equal leakage paths and thereby maintain a state of equilibrium in the tube, at which time it is non-conductive, although sensitive to any capacitive change between its grid and anode to effect conduction. The same is true with respect to the tube 31 except in the reversed order. Here, the capacity 41 provides the leakage path between anode 36 and grid 49, whereas the condenser 42 provides the counter-balancing leak, age path between cathode 38 and grid 49. Condensers 52 and 51 are small with respect to the operating condensers 42 and 41 serving merely as trimmer capacitors to compensate for capacitive differences that may exist when the two operating condensers are in the same position and also for the capacity introduced by the conductors.

Referring to the operation of the control system, let it be assumed that it is desired to move the tuning condenser l in counterclockwise direction to the extent represented by three di- Visions On the dial 3. To do this, the condenser 42 at the remote point is turned also in a counterclockwise direction to the extent represented by three divisions on the dial 59 which is attached to the shaft 60 thereof. The result will be an increase in the capacity of the condenser 42 providing a leakage path of lower resistance between anode 21 and grid 46 or the tube 29. The latter becomes immediately conductive permitting current to flow to the winding 20 of the relay it. This, in turn, closes the circuit between contacts l2 and I2, energizing the motor 5 through its field winding 8, which is so poled as to rotate the tuning condenser l of the radio receiver through a suitable reduction gearing also in a counterclockwise direction. The motion thereof rotates the condenser 41 to increase its capacity similarly. When this capacity reaches the corresponding value of the capacity 42, the leakage path between cathode 29 and grid 46 will be increased until it equals that offered by the condenser 42, thereby reestablishing again the condition of balance or electrical equilibrium. The tube 26 becomes non-conductive, releasing the relay l8, which disconnects the motor winding 8. It may well be mentioned here that the capacity increase of the condenser 42 while it provided a leakage path of lower resistance between the grid and cathode of the tube 26, it also provided a similar path between the cathode I9 and grid 49 of the tube 91, whereby this tube became biased to non-conduction and its sensitivity was reduced to a certain degree. Hence, when the condenser 41 is moved by virtue of the actuation of the motor, the increase 01 this capacity which provides an increase of leakage path between anode 96 and grid 49 of the tube 31 does not cause actuation of the tube 31 due to the bias aforementioned. When equilibrium is re-established, the capacitive leakage paths in both tubes are again neutralized and the sensitivity of both tubes restored.

Considering control in the opposite direction,

the clockwise setting of the dial 59 will cause a capacitive setting of the condenser 42 of lower capacity resulting in a higher resistance leakage path between grid and anode of tube 28. A higher resistance leakage path between anode and grid is equivalent, in efl'ect, to a lower resistance leakage path between cathode and grid, which as was stated before, provides a certain bias for the tube. Consequently, tube 26 will not be conducting; as a matter of fact, its sensitivity will be lowered. Furthermore, the capacitive change of thecondenser 42 provides also a higher resistance leakage path between cathode 39 and grid 49 of tube 41. .A high resistance leakage path between these electrodes, in eilect, ls equal to a lower resistance path between anode I9 and grid 49 which will trigger the tube 31 into conductive action, whereby the relay l9 will be energized, closing the contacts l5 and II and switching into the circuit the field winding 9 oi the motor 5. The rotation of the tuning condenser I will now be energized in a clockwise direction until the condenser 41 will be lowered in capacity to a degree which will counter-balance the higher resistance cathode 38 of tube 31. In other words, the decrease of capacity of condenser 41 will decrease the leakage path between anode 96 and grid 49. When a tate of equilibrium is reached, the tube will be non-conductive and the relay l9 disconnects the motor from the circuit.

I claim as my invention:

1. In a control system, apparatus to be controlled as to its movement, control means for said apparatus including a pair of discharge tubes connected back-to-back, the space current conductivity of which initiates movement of said apparatus, individual'energizing circuits for said tubes, a circuit capacitively interconnecting said tubes for maintaining electrical equilibrium thereby preventing space current conductivity of said tubes, capacitive means at a control point for disturbing said equilibrium and thereby initiating movement of said apparatus and capacitive means coactively associated with said apparatus for restoring said equilibrium upon predetermined movement thereof.

2. In a control system, apparatus to be controlled as to its movement in one direction and in the opposite direction, control means for said apparatus including a pair of discharge tubes connected back-to-back, the space current conductivity of one of said tubes initiating movement of said apparatus in one direction and the space current conductivity of the other of said tubes in the other direction, circuits for individually energizing said tubes, a second circuit capacitively interconnecting said tube for maintaining electrical equilibrium and thereby preventing space current conductivity of said tubes, means at a control point for effecting a change of capacitance in said second circuit thereby disturbing said equilibrium, said last mentioned means being operable upon increase of capacitance to cause conductive energization of one of said tubes and upon decrease thereof to cause conductive energization of the other of said tubes, and means coactively associated with said apparatus for effecting a capacitance change in said second circuit in such sense as to restore said equilibrium upona predetermined movement of said apparatus.

3. In a control system, apparatus to be controlled as to it movement in one direction and in the opposite direction, control means for said apparatus including a pair of discharge tubes connected back-to-back, the space current energization of one of said tubes initiating movement 01' said apparatus in one direction and the space current energization of the other of said tubes in the other direction, circuits for individually energizing said tubes, a second circuit capacitively interconnecting said tubes for maintaining electrical equilibrium and thereby preventing the energization of said tubes, means at a control path between grid 49 and point for eil'ecting a change of capacitance in said second circuit thereby disturbing said equilibrium, said last mentioned means being operable upon increase of capacitance to cause energization of one of said tubes and upon decrease thereof to cause energization of the other of said tubes, and mean coactively associated with said apparatus for eil'ecting a capacitance change in said second circuit in such sense as to restore said equilibrium upon movement of said apparatus determined by the extent of said capacitive change at said control point.

4. In a control system, a pair of discharge tubes 4 each having an anode, a cathode and a grid electrode, an energizing circuit for each of said tubes between the anode and cathode including in series means responsive to current flow between said electrodes, apparatus controlled by said means, a. circuit interconnecting the anode and grid electrode of one of said tubes and the grid electrode and cathode of the other or said tubes including impedance elements for effectively counter-balancing their grid anode and grid cathode paths, respectively, producing thereby a state of electrical equilibrium at which said tubes are nonoonducting, means associated with one of said elements ior changing the impedance between anode and grid electrode of one of said tubes disturbing thereby said equilibrium and initiating current flow in one of said tubes, and means coactively v associated with said apparatus for changing the impedance between grid and cathode of the other of said tubes thereby restoring said equilibrium upon predetermined actuation of said apparatus.

5. In a control system, a controlled apparatus adapted to be rotated in both directions, a pair of discharge tubes, each having at least an anode, a cathode, and a control electrode, circuit arrangement for causing rotation of said apparatus in one direction upon conductive energization of one of said tube and in the other direction upon conductive energization of the other of said tubes, means for establishing electrical equilibrium between said tubes whereby said tubes are non-conducting comprising a pair of variable capacities, one of said capacities being connected between certain electrodes of said tubes and located at a remote point from said apparatus and the other of said capacities connected between similar electrodes of said tubes and interlinkedwith said apparatus for rotary movement of capacitive change, whereby a desired change of said remote capacity efiects a disturbance in said equilibrium causing rotation of said apparatus and correspondin rotation of said other capacity restores said equilibrium upon said last-mentioned capacity being adjusted to a value sufllcient for neutralizing the eflect of said first-mentioned capacity.

6. In a control system, a controlled apparatus adapted to be rotated in both directions, a pair of discharge tubes, each having at least an anode, a cathode, and a control electrode, circuit arrangement for causing rotation of said apparatus in one direction upon conductive energization of one of said tubes and in the other direction upon conductive energization of the other of said tubes.

means for establishing electrical equilibrium be-' tween said tubes whereby said tubes are nonconducting comprising a pair of variable capacities, one of said capacities being connected between control electrodes and the anode of one of said tubes and between control electrode and cathode of the other of said tubes and located at a remote point from said apparatus and the other of said capacities being connected between control electrode and cathode of said first-mentioned tube and between control electrode and anode of said second mentioned tube and interlinked with aid apparatus for rotary movement of capacitive change, whereby a desired change of said remote capacity effects a disturbance in said equilibrium causing rotation of said apparatus and corresponding rotation of said other capacity restores said equilibrium upon said last-mentioned capacitybeing adjusted to a value corresponding to that of said first-mentioned capacity.

7. In a control system, a controlled apparatus adapted to be rotated in both directions, a pair of. discharge tubes each having anode, cathode and grid electrodes, circuit arrangement for causing rotation of said apparatus in one direction upon conductive energization of one of said tubes and in the other direction upon conductive energization of the other of said tubes, a pair of adjustable condensers one being located at a remote point and effective to produce a capacitive leakage path between anode and grid electrode of one of said tubes, and simultaneously a similar path between cathode and grid electrode of the other of said tubes, the other of said condensers being attached to said apparatus for varying its capacity upon rotation and effective to produce a capacitive leakage path between cathode and grid electrode of said first tube, and correspondingly between anode and grid electrode of said second tube, the effective capacitive reactance of said condensers at a certain adjustment being complementary to balance opposing efiects of said leakage path, thereby establishing a state of electrical equilibrium between 'said tubes, said tubes being then non-conductive, manually adjusting means for said first condenser for creating a leakage path between grid and anode of one of said tubes greater than said path between grid and cathode thereof. causing conductive energization of one of said tubes and rotation of said controlled apparatus in one direction, and upon movement of said control apparatus a corresponding adjustment of said second condenser for producing a leakage path between cathode and grid electrode of said tube opposing the eifect of said first leakage path upon adjustment of said condenser to a predetermined value whereby said state of equilibrium is re-established.

8. In a control system, a motor, a source of energy therefor, switching means for energizing said motor for operation in one direction and switching means for energizing said motor for operation in the reverse direction, a pair of gridglow tubes each having an anode, a cathode and a grid electrode, individual energizing circuits for said tubes between anode andcathode electrodes, one of said circuits including said first switching means and the other of said circuits said second switching means, means for controlling the direction and extent of rotation of said motor comprising a variable capacity effectively connected between anode and grid electrodes of one of said tubes and between grid and cathode electrode of the other of said tubes, a second variable capacity effectively connected between grid and cathode of said first-mentioned tube and between grid and anode of said second tube, a change of said first capacity in one direction being effective for operative energization of one of said tubes and in the otherdirection of operative energizetion of the other of said tubes causing actuation of said motor in corresponding directions, said second capacity being mechanically interlinked with the movement of said motor and operable in cancelling the effect of said first capacity.

9. In a control system, apparatus to be controlled as to its movement, control means for said apparatus including a pair of discharge tubes connected back-to-back, the space current conductivity of which initiates movement of said apparatus, individual energizing circuits for said tubes, a circuit including an adjustable impedance element interconnecting said tubes for maintaining electrical equilibrium and thereby preventing space current conductivity of said tubes, adjustable impedance means at a control point for disturbing said equilibrium and thereby initlating movement of said apparatus, and means coactively associated with said apparatu for effecting adjustment of said first mentioned impedance means thereby restoring'said equilibrium upbn predetermined movement of said apparatus.

FREDERICK E. BARTHOLY. 

